In recent years, a mobile phone has been widely spread which is equipped with a liquid crystal device capable of displaying high-precision image data. In such a mobile phone, during telephone directory calling, during an incoming call, or during talking on the phone, it has become common to display a thumbnail image, together with name information and telephone number information of a communication partner.
In addition, there is a desire to use telephone directory data including thumbnail image data which is used in a mobile phone, even in a cordless phone that is used in home. Here, the telephone directory data employs a data structure including a plurality of records, with a data set including at least name information, telephone number information, and thumbnail image data of a communication partner as a single record (a data unit to be managed). Information such as the nationality, the address, the e-mail address, the affiliation company and the date of birth of the communication partner, in addition to the name information, the telephone number information, and the thumbnail image data, may be included in the record information of the telephone directory data.
In PTL 1, a telephone directory data transfer system is described in which a mobile phone and an extension telephone (or a general subscriber phone) are coupled and can transfer telephone directory data to each other.